The primary goal is to develop new treatment strategies for childhood leukemias and lymphomas. The following projects are currently underway or in preparation: 1) cDNA Microarray Analysis of Pediatric Leukemias 2) Pilot Study of Non-Myeloablative, HLA-Matched Allogeneic Stem Cell Transplantation in Pediatric Leukemias and Lymphomas 3) Immunotoxins for Treatment Of Leukemias And Lymphomas In Childhood